Simplify order_tag in TagOrderStore
Simplify order_tag in TagOrderStore

such that:
 - it takes a targetTag to be replaced instead the previous tag to insert after
 - it optionally displaces the targetTag before or after the inserted tag

matrix-org/matrix-react-sdk,aperezdc/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,aperezdc/matrix-react-sdk,aperezdc/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,matrix-org/matrix-react-sdk,aperezdc/matrix-react-sdk